The present invention relates to a camera controller which can be used for a camera using a film, a digital camera, etc.
Various types of camera controllers using CMOS analog circuits for cameral control have been developed in the prior art.
U.S. Pat. No. 5,557,363, for example, discloses a camera controller wherein a microcomputer comprising a CPU and peripheral circuits, and a CMOS analog circuit are formed on a single semiconductor chip by a low-cost, general-purpose CMOS process.
In the camera controller disclosed in U.S. Pat. No. 5,557,363, a remote control reception circuit is fabricated by a CMOS process. As a result, compared to the use of a conventional bipolar process, degradation in characteristics due to a variance in the process is serious. For example, the distance over which a remote control signal of the remote control reception circuit can be sent is shortened, and a problem arises in that a remote control operation can be performed only in a short range.
The problem of degradation in characteristics is faced by not only the remote control reception circuit but also by other analog circuits such as a distance measurement circuit and a light measurement circuit.
To deal with this problem, there is an idea that the gain of the remote control reception circuit, the central frequency f0 of a band-pass filter (BPF), etc. is adjusted.
In a specific method of adjustment, resistance elements, etc. on an IC chip are trimmed by laser trimming.
Alternatively, an external resistor may be provided for an IC chip and, with a proper resistance value of the external resistor chosen, the resistor is connected to the IC chip. Or a variable resistor may be connected and adjusted.
In the case of using the laser trimming method, however, large-scale, high-cost equipment is required. Consequently, the cost of a device, such as a camera, having the remote control reception circuit is increased.
On the other hand, the method of choosing the resistance value of the external resistor or adjusting the variable resistor requires additional adjustment work, resulting in an increase in cost.
The method of the present invention is to provide a camera controller wherein a variance in CMOS analog circuits can be corrected and degradation in characteristics can be prevented, without incurring an increase in manufacturing cost.
According to a first aspect of the invention, there is provided a camera controller comprising:
a microcomputer;
a measuring circuit for a camera, the measuring circuit acquiring information necessary for an operation of the camera and having variable electrical characteristics; and
an alteration circuit, controlled by the microcomputer, for altering the electrical characteristics of the measuring circuit for the camera, wherein the microcomputer and the circuits are fabricated on a single semiconductor substrate.
According to a second aspect of the invention, there is provided a camera controller comprising:
a microcomputer;
a measuring circuit for acquiring information necessary for an operation of a camera; and
an alteration circuit for altering electrical characteristics of the measuring circuit, wherein the microcomputer and the circuits are fabricated on a common semiconductor substrate.
According to a third aspect of the invention, there is provided a camera controller comprising:
a digital circuit for controlling an operation of a camera;
a measuring circuit for acquiring information necessary for the operation of the camera; and
an alteration circuit for altering electrical characteristics of the measuring circuit,
wherein the circuits are fabricated on a common semiconductor substrate.
According to a fourth aspect of the invention, there is provided a camera controller comprising:
a microcomputer;
an analog circuit for a camera; and
an alteration circuit for altering electrical characteristics of the analog circuit,
wherein the microcomputer and the circuits are fabricated on a common semiconductor substrate.
According to a fifth aspect of the invention, there is provided a controller for a remote-control camera, the controller comprising:
reception means for receiving the remote control signal transmitted from a transmission means;
control means for controlling an operation of the camera on the basis of an output from the reception means; and
setting means, controlled by the control means, for setting electrical characteristics of the reception means.
According to a sixth aspect of the invention, there is provided a method of adjusting a camera system comprising:
a camera controller in which a digital circuit for controlling an operation of a camera, a measuring circuit for acquiring information necessary for the operation of the camera, and an alteration circuit for altering electrical characteristics of the measuring circuit are fabricated on a common semiconductor substrate; and
a non-volatile memory for storing adjustment data for setting the electrical characteristics of the measuring circuit which are altered by the alteration circuit,
the method comprising the steps of:
inputting predetermined information to the measuring circuit;
acquiring adjustment data for the alteration circuit for optimizing an output of the measuring circuit at the time of using the camera, on the basis of the output of the measuring circuit when the predetermined information has been input; and
storing the adjustment data in the non-volatile memory.
According to a seventh aspect of the invention, there is provided a camera controller comprising:
means for performing measurement for acquiring information necessary for an operation of a camera;
means for altering electrical characteristics of the measuring means; and
means for performing a control by altering electrical characteristics of the altering means on the basis of a measurement result of the measuring means,
characterized in that the measuring means, the altering means and the control means are fabricated on a single semiconductor substrate.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.